In a televised, 50-minute speech, Mr. Nasrallah said the drone, which was shot down by Israeli forces, had been designed in Iran and assembled by Hezbollah experts in Lebanon.

“It is our right to send other drones whenever we want,” Mr. Nasrallah said, noting that Israel frequently violated Lebanese airspace. “It was not the first time and it will not be the last.”

Hours earlier, Israel’s prime minister, Benjamin Netanyahu, accused Hezbollah in the episode, saying that Israel had “thwarted over the weekend Hezbollah’s attempt” to penetrate its airspace. The group has sent a drone over Israel at least once before.

There was no immediate official reaction from Israel to Mr. Nasrallah’s speech, or warnings about the need for a military response against Hezbollah in Lebanon. If anything, there seemed to be an attempt to point a finger at Hezbollah’s patron, the more distant Iran.

“It should come as no surprise that the military machine of Hezbollah in Lebanon is substantially made in Iran,” said one senior official, who was not authorized to comment publicly on the matter.

Mr. Nasrallah’s speech was closely watched because of fears that Hezbollah, a longtime ally of Syria and Iran, might provoke a clash with Israel to distract attention from Syria’s crackdown on the nearly 19-month uprising there. Hezbollah has been accused by the United States government, Syrian rebels and Lebanese rivals of assisting the Syrian president, Bashar al-Assad, in his crackdown.

The possibility of Syria becoming a proxy war, with involvement from Hezbollah and Iran on one side and powers like Saudi Arabia, Turkey and Qatar on the other, is one of many factors that could fuel regional escalation of the conflict.

Mr. Nasrallah denied that he had ordered his fighters into Syria, but said the group reserved the right to join the battle in the future.

At the same time, he appeared to subtly distance himself from Mr. Assad. He never mentioned Mr. Assad’s name — speaking only of “the Syrian regime” — and refrained from praising Syria’s government, as he has in the past, as a pillar of resistance against Israel’s occupation of Palestinian territories.

Photo

Hassan Nasrallah described the drone flight as an unprecedented achievement.Credit
Hussein Malla/Associated Press

“As of now, we have not fought alongside the regime,” he said, adding, “We don’t know about the future.”

He obliquely acknowledged that some individual Hezbollah militants may have fought there. Because of the vagaries of post-colonial borders, he said, more than 30,000 Lebanese live in Syria, including Shiites, some of whom are members of Hezbollah and veterans of its wars. Some of them, he said, have fought to defend against rebel attacks on their homes and villages, including kidnappings and mortar attacks on Syrian checkpoints protecting the villages.

“What can we expect them to do?” he asked. He said that a senior Hezbollah operative who died recently while performing “jihadist duties” was killed in an accidental weapons explosion, not fighting in Syria.

Hezbollah, which was formed 30 years ago to fight the Israeli occupation of southern Lebanon and which battled Israel again in 2006, has long relied on Syria as a conduit and supplier of arms. With its Shiite Muslim base, the group is a natural ally of Mr. Assad’s ruling Alawites, who practice an offshoot of Shiism.

But with many Lebanese Sunnis supporting the Sunni-led Syrian uprising, Hezbollah is also wary of inflaming sectarian tensions at home. Mr. Nasrallah said that Syrians of many sects were under threat from the Syrian uprising, in which some fighting units have taken a sectarian tone.

It was a reminder that independent of Mr. Assad’s fate, Hezbollah may see Shiite or Lebanese interests as at stake in Syria, like preserving access to an important Shiite shrine in Damascus and defending minority groups, as well as Hezbollah’s arms flow.

Hezbollah’s image as a champion of the oppressed in the wider Arab and Muslim world has been tarnished by its support for Mr. Assad against a popular revolt, a stance that critics say exposes the group’s hypocrisy. The speech appeared aimed to show that Hezbollah would remain a force against Israel even if Mr. Assad falls or is discredited.

Talal Atrissi, a political science professor close to Hezbollah, said Mr. Nasrallah was trying to show that “Hezbollah’s priority for the time being is Israel despite everything that is happening,” and to say, “We’re not going to fall with the regime.”

Mr. Atrissi said the speech was also aimed at Syrian rebels and their Sunni Muslim supporters, to convey that Hezbollah had the means to stand up to threats and attempts to weaken its influence.

Benedetta Berti, an expert on Hezbollah at the Institute for National Security Studies in Tel Aviv, said Hezbollah taking responsibility for the drone proved Israeli suspicions that “yes, 2006 was somewhat of a blow to Hezbollah, but in the past few years, they’re more than compensated.”

“They’ve upgraded their arsenal,” she said. “This is what we knew, at least what we believed. It’s one more indication that Hezbollah has been rearming and retraining and getting ready for Round 2.”

Reporting was contributed by Hania Mourtada and Hwaida Saad from Beirut, and Isabel Kershner and Jodi Rudoren from Jerusalem.

A version of this article appears in print on October 12, 2012, on page A10 of the New York edition with the headline: Hezbollah Says It Flew Drone Into Israel, and Describes Iran as Its Designer. Order Reprints|Today's Paper|Subscribe